Ask any simple monk or village priest in Greece, who most likely has never even seen a Protestant, much less actually been one himself.
Ask any babushka in a church in Russia. As for the Serbs, let's not even go there!
Bad feelings towards Catholics among some Orthodox is far too complex to be dismissed as "Protestant baggage".
I wrote that there were also those who had other (legitimate) reasons for their grievances with Catholicism, because of the history and the attempts from Catholic Empires to dominate them.
I still think it's no sense to live in the past for ever, almost all the nations of this world have suffered injustice by other empires and their religions. What I meant is that, when you talk to Serb, as you said, they will tell you their legitimate reasons (the genocide of Serbs by Latin rite Croats), but when they realize that Catholicism is not only Croat and that there are hunderds of ethnic groups who are Catholic and who have nothing to do with the Croats, things would change, and when the religious reasons come to discussion, prejuidces are often left aside.
An inverse example, Montenegrin Albanians and Catholic Kosovars seem to hate everything which is Orthodox, but this is due to the Serrbian persecution and the conflicts they have with them, but when they realize that in the south of Albania there are lots of Orthodox Albanians, thery would probably not generalize and say all orthodox are Serbs.
